The present invention relates to processes for producing cycloalkenyl derivatives from the reaction of acrolein, methacrolein and alkyl vinyl ketone, all formed in situ, with conjugated dienes in good yields.
The Diels-Alder reaction is well known in the field of organic chemistry, and the classic example thereof is the reaction of a conjugated diene with a conjugated alkylene carbonyl compound to provide a cyclohexene derivative. Since the original reaction was set forth, there have been many variations of the reaction.
U.S. Pat. No. 3,341,601 issued on Sept. 12, 1967, relates to a process for producing Diels-Alder adducts of conjugated dienes and carbonyl compounds, wherein the adducts are produced by contacting a reaction mixture comprising a conjugated diene and a carbonyl compound having at least two alpha-hydrogen atoms with a condensation-dehydration catalyst at elevated temperatures according to the following reaction: ##EQU1## Although an in-situ formed methacrolein material is shown to be produced and act as a dienophile in the disclosure of U.S. Pat. No. 3,341,601, the dienes used in this reaction are relatively simple in nature.
Although the reaction of long chain aldehydes with formaldehyde in the presence of an amine catalyst is disclosed in U.S. Pat. No. 3,463,818, no suggestion of the carrying out of a Diels-Alder reaction is set forth therein. U.S. Pat. No. 3,463,818 relates to a process for producing alpha-methylene and alpha-methyl aldehydes and alcohols by reaction, in the presence of an amine catalyst, an aldehyde such as citronellal with formaldehyde.
U.S. Pat. No. 2,373,568 shows the Diels-Alder reaction of methacrolein and cyclopentadiene under pressure at about 140.degree.C to provide a material with a camphoraceous aroma and the further reaction of the Diels-Alder product with acetone and sodium methylate to provide a product with a floral-type odor. Vaughan et al in J.A.C.S. 74, 5355 shows the reaction of mesityl oxide and cyclopentadiene produced in situ by thermal depolymerization of the dimer to provide an unsaturated ketone by carrying out the reaction at 160.degree.C for 12 hours to provide a 21% yield, based upon mesityl oxide.
Chemical Abstracts 47, 12271e shows a diene condensation at 160.degree.C in the presence of pyrolgallol.
Chemical Abstracts, Vol. 56, 4692c discloses the Diels-Alder reaction of allo-ocimene with appropriate carbonyl compounds such as acrylonitrile to yield naphthalene derivatives in the presence of hydroquinone at 160.degree.-200.degree.C for a period of time of from 21/2 hours up to 6 hours in 50-71.5% yields.
Acrolein and allo-ocimene have been shown to react to form Diels-Alder adducts in the presence of hydroquinone by B. A. Arbuzov and A. R. Vil'chinskaya (State Univ., Kazan). Zhur. Obshchei Khim. 31, 2199-204 (1961).
A. R. Vil'chinskaya and B. A. Arbuzov, Voprosy Khim. Terpenov i Terpenoidov, Akad. Nauk Litovsk, S.S.R., Trudy Vsesoyuz, Soveshchaniya, Vil'nyus 1959, 201-7 (Pub. 1960) also show reaction products of crotonaldehyde with allo-ocimene (also see Vol. 55, Chemical Abstracts, 16495d). The Diels-Alder reaction of allo-ocimene with acrolein or crotonaldehyde is also set forth in Vol. 29, Chemical Abstracts 6888.sup.6 (Abstract of Berichte 68B, 1435-8 (1935). Also suggested in the Berichte article is the condensation of the thus produced reaction products with acetone and other ketones to form "odoriferous ionone-like compounds". U.S. Pat. No. 3,067.244 discloses, interalia, the catalyzed condensation of cyclopentadiene with acrolein.
British Patent 896,039 entitled "Method of Producing Derivatives of the 1,1-Dimethyl-Octahydronaphthalene Series" discloses the generic process: ##SPC2##
wherein R.sub.2, R.sub.3 and R.sub.4 are disclosed to be same or different hydrogen atoms or alkyl and R.sub.1 is disclosed to be hydroxy, alkyl or alkoxy. The British patent discloses this process to be useful for producing products "resembling the well known class of violet perfumes". Indeed, Example 5 of the British Patent alleges that the compound 1,1,6,6-tetramethyl-7-ketomethyl-octalin produced by (1) reacting myrcene and mesityl oxide thermally followed by (2) subsequent cyclization, has a pleasant "woody ambergris smell".
Further, cyclization reactions of Diels-Alder adducts of myrcene and a dienophile are set forth in U.S. Pat. No. 3,076,022. This patent discloses interalia, preparation of the thermal Diels-Alder adduct of myrcene and methyl isopropenyl ketone and subsequent acid cyclization to a product said to possess "an intense ambergris-like note."
Ohloff (Chemistry of Odoriferous and Flavoring Substances) pp. 185-240 (at page 192) Fortschritte & der Chemischen Forschung Vol. 12, Part 2, 1969, discloses a compound having the structure: ##SPC3##
Ohloff indicates that materials of this nature have "resiny odors" like olibanum, with amber type undertones.
This invention relates to the preparation of synthetic woody or floral, melony, or green, woody, herbaceous or citrusy fragrance ingredients for perfumes and cosmetics and to certain novel mixtures produced by means of said preparation. More particularly, the invention has to do with a process for the preparation of floral, melony, or green, woody, herbaceous or citrusy fragrance compositions and intermediates used in the preparation of amber-like or fruity, or fruity-amber, or woody, or green, or yeasty, or buttery, or ionone-like or pineapple-like fragrance compositions for use in perfumery.
The novel mixtures which this invention covers are exemplified as follows:
i. mixture of compounds having the structures: ##SPC4##
ii. mixture of compounds having the structures: ##SPC5##
iii. and a mixture of compounds having the structures: ##SPC6##
The invention also covers processes for producing, directly, Diels-Alder adducts which process comprises intimately admixing:
i. A conjugated diene selected from the group consisting of alpha-terpinene, allo-ocimene, cyclopentadiene and myrcene; with PA1 i. alpha-terpinene; PA1 ii. allo-ocimene; PA1 iii. cyclopentadiene; or PA1 iv. myrcene PA1 i. acetone; PA1 ii. acetaldehyde; PA1 iii. propionaldehyde; or PA1 iv. methyl-ethyl ketone PA1 i. paraformaldehyde (a formaldehyde polymer of high molecular weight which depolymerizes at the reaction temperature); PA1 ii. formalin (a 40% solution of formaldehyde containing a small amount of methanol); or PA1 iii. acetaldehyde PA1 Methyl ethyl amine PA1 Methyl n-propyl amine PA1 Methyl isopropyl amine PA1 Ethyl isopropyl amine PA1 Ethyl n-butyl amine PA1 Ethyl t-butyl amine PA1 Pyrrolidine PA1 Piperidine PA1 Morpholine
ii. a carbonyl group-containing compound selected from the group consisting of acetone, acetaldehyde, propionaldehyde and methyl-ethyl ketones; with
iii. an aldehyde source selected from the group consisting of a formaldehyde source and an acetaldehyde source; and
iv. a secondary amine catalyst.
A particular feature of my invention is that the dienophile (the condensation products which are obtained by the reaction of the carbonyl-group-containing compound and the aldehyde source) immediately reacts with the conjugated diene, thus forming the Diels-Alder adduct. The dienophiles may be considered as being acrolein, methacrolein, methyl vinyl ketone and 3-methyl pent-3-en-2-one. The decisive advantages of the instant process are:
i. many low molecular weight substituted acroleins and alpha, beta-unsaturated ketones are skin, eye and respiratory irritants and therefore, at best, unpleasant to handle;
ii. the great reactivity of acrolein, alphasubstituted acroleins and low molecular weight alpha-beta-unsaturated ketones makes them unsuitable for storage without decomposition; and
iii. more efficient processing is accomplished by combining the formation of the dienophile with the Diels-Alder reaction without having two separate reactions to carry out in a manufacturing operation.
The resulting adducts are useful per se as perfumery materials, having green floral odors or they may be further reacted as by cyclization as further exemplified herein to form other materials which are useful in perfumery for their amber-like or fruity or fruity-amber or woody, or green or yeasty or buttery or ionone-like or pineapple-like fragrances and which are useful in tobacco because they modify the aromas of the mainstream and sidestreams of a smoking article on smoking by imparting to the aroma of such mainstream and sidestream sweet, spicey, cedarwood-like notes.
The basic process of our invention involves heating a mixture of a conjugated diene with the carbonyl group-containing compound, and the aldehyde source, and a secondary amine catalyst in an autoclave at pressures substantially greater than atmospheric at temperatures in the range of 120.degree.C up to 200.degree.C for a period of time of from 2 hours up to 8 hours.
The conjugated diene in our invention is specific and may be one of the following materials;
Myrcene is commercially available in purities of 70% and upwards, and it can be used in this form. It is generally preferred in the practice of this invention to use commercial myrcene (approximately 72-77% purity), although, obviously, purified myrcene may be used. Such a purification is readily accomplished by fractional distillation.
The carbonyl group-containing compound is also specific in the process of our invention and may be either:
It is preferred that the purity of the aldehyde or ketone be between 90 and 100%; preferably as close to 100% as possible, in order to avoid purification problems at the end of the reaction.
The aldehyde source which is selected from the group consisting of a formaldehyde source and an acetaldehyde source may be one of the following materials:
The catalyst used is a secondary amine, preferably diethyl amine or dimethyl amine which may be in the form of a salt of the amine with an inorganic acid such as dimethyl amine sulfate and diethyl amine sulfate. Other secondary amines which are suitable for the instant reaction are as follows:
The amine catalyst may be introduced into the reaction mass as such, in the gaseous phase, or in solution, for example, in aqueous solution. The catalyst, when used as a salt, may be preformed or it may be formed in-situ in the reaction mass. Thus, for example, the secondary amine may be first introduced into the reaction mass, followed by the mineral acid which will form the amine salt.
Theoretically, the mole ratio of conjugated diene: carbonyl group-containing compound:aldehyde source is 1:1:1. Nevertheless, it is preferred to use a slight excess of aldehyde source with respect to carbonyl group-containing compound and conjugated diene. Also, it is preferred to use a slight molar excess of carbonyl group-containing compound with respect to conjugated diene. The mole ratio of secondary amine: conjugated diene is preferably between 1:20 and 1:5. Excess amine catalyst gives rise to problems concerning work-up after the completion of the reaction. Too little amine catalyst will cause the reaction to be inordinately slow, and therefore commercially impractical.
The reaction temperature can vary from 120.degree.C up to 200.degree.C, with a temperature range of 150.degree.-180.degree.C being preferred. At lower temperatures longer reaction times are required. In view of the nature of the catalyst used, the temperature of 120.degree.-200.degree.C gives rise to the use of pressures higher than atmospheric. Accordingly, the use of pressure reaction vessels are required.
The order of addition of reactants and catalyst is not critical; however, it is preferred to pre-mix the conjugated diene, aldehyde source and carbonyl group-containing compound prior to addition of the secondary amine catalyst. Furthermore, it is preferred to pre-mix the secondary amine with the conjugated diene, carbonyl group-containing compound and aldehyde source prior to addition of the mineral acid (when desired) whereby the catalyst salt will be produced.
In carrying out the reaction, it is preferable to use an acid pH of between about 3 and about 6. Nevertheless, a pH of up to 8 will not be detrimental to the reaction.
The following table sets forth the type of reaction product which will be produced using the aforementioned reactants: ##SPC7##
When the reaction is substantially complete, the reaction mass is then washed and the organic layer is separated and distilled.
The distilled product may be used "as is" in perfumery or it may be, in certain cases, further reacted, as by cyclization of the compound: ##SPC8##
using concentrated phosphoric acid to form a compound having the structure: ##SPC9##
The novel mixtures of our invention have woody and woody, green, herbaceous aromas. A number of the products produced by our process which are not novel, have green, floral odors for use in such perfume compositions as rose, violet and lily-of-the-valley. A number of intermediates prepared by the process of our invention when cyclyzed give rise to compounds having intense and persistent amberlike, fruity, or fruity amber or woody or green or yeasty or buttery or ionone-like or pineapple-like odors.
The products produced by the process of my invention, including my novel mixtures, and an auxiliary perfume ingredient including, for example, alcohols, aldehydes, nitriles, esters, cyclic esters and natural essential oils may be admixed so that the combined odors of the individual components produce a pleasant or desired fragrance. Such perfume compositions usually contain (a) the main note or the "bouquet" or foundation stone of the composition; (b) modifiers which round off and accompany the main note; (c) fixatives which include odorous substances which lend a particular note to the perfume throughout all states of evaporation and substances which retard evaporation; and (d) topnotes which are usually low boiling fresh smelling materials.
In perfume compositions, the individual component will contribute its particular olfactory characteristics but the over-all effect of the perfume composition will be the sum of the effects of each of the ingredients. Thus, the products produced by the process of my invention including my novel mixtures can be used to alter the aroma characteristics of a perfume composition, for example, by utilizing or moderating the olfactory reaction contributed by another ingredient in the composition.
The amount of the products produced by the process of my invention including my novel mixtures which will be effective in perfume compositions depend on many factors including the other ingredients, their amounts and the effects which are desired. It has been found that perfume compositions containing as little as 0.05% of the products produced by the process of my invention, including my novel mixtures, or even less can be used to impart an amber-like, fruity, or fruity amber or woody or green or yeasty or buttery or ionone-like or pineapple-like type scent odor to soaps, cosmetics and other products. The amount employed can range up to 5% of the fragrance components and will depend on considerations of cost, nature of the end product, the effect desired on the finished product and the particular fragrance sought.
The products produced by the process of my invention including my novel mixtures are useful in perfume compositions as olfactory components in detergents and soaps; space odorants and deodorants; perfumes; colognes; toilet water; bath preparations such as bath oils and bath solids; hair preparations such as lacquers, brilliantines, pomades and shampoo; cosmetic preparations such as creams, deodorants, hand lotions and sunscreens; powders such as talcs, dusting powders, face powders and the like. When used as an olfactory component of a perfumed article, as little as 100 parts per million of the products produced by the process of my invention, including my novel mixtures, will suffice to impart low keyed "amber-like, fruity, or fruity-amber or woody or green or yeasty or buttery or ionone-like or pineapple-like characteristics. Generally, no more than 0.5% of the products produced by the process of my invention, including my novel mixtures based on the ultimate end product is required in the perfume composition.
In addition, the perfume composition or fragrance composition of this invention contain a vehicle or carrier for the products produced by the process of my invention, including my novel mixtures. The vehicle can be a liquid such as an alcohol, a non-toxic alcohol, a non-toxic glycol or the like. The carrier can also be an absorbent solid such as a gum (e.g., gum arabic) or components for encapsulating the composition (such as gelatine).
It will thus be apparent that the products produced by the process of my invention, including my novel mixtures, can be utilized to alter the sensory properties, particularly organoleptic properties such as flavor and/or fragrances of a wide variety of consumable materials.
In making the perfumes using the materials produced by the instant invention, such materials can be combined with "auxiliary perfume adjuvants," including one or more of many types of odor materials such as bergamot oil, vetiver oil, patchouli oil, sandalwood oil, oakmoss and floral musk. The materials produced according to this invention can also be combined with a customary perfume auxiliary adjuvants such as natural oils, synthetic oils, aldehydes, ketones, carboxylic acid esters, aryl alcohols, alkanols, lactones, saturated hydrocarbons, unsaturated hydrocarbons, fixatives, solvents, dispersants, surface active agents, aerosol propellants and the like.
The following examples serve to illustrate embodiments of our invention as it is now preferred to practice it. It will be understood that these examples are illustrative, and the invention is to be considered restrictive thereto only as indicated in the appended claims.